A polycarbonate resin molded article is transparent, and is excellent in heat resistance and mechanical strength such as impact resistance, and hence the molded article has been widely used as an industrial transparent material in the fields of, for example, electricity, machinery, and automobiles. In addition, the molded article has been used as a plastic for an optical material in, for example, a lens or an optical disc.
The polycarbonate resin molded article is excellent in mechanical strength, but its strength is lower than that of a glass or a ceramic. Accordingly, when mechanical strength is needed, the mechanical strength of the molded article is improved by adding, for example, a glass filler.
However, a polycarbonate resin molded article reinforced with a general glass filler in the related art has involved a problem in that its transparency reduces.
To overcome the problem, a study has been made on the maintenance of the transparency of a polycarbonate resin molded article through the following (see, for example, Patent Documents 1 to 5). The refractive indices of a polycarbonate resin and a glass filler are set to substantially the same refractive index by changing the composition of the polycarbonate resin, adding an additive to a polycarbonate resin composition, or changing the composition of the glass filler.
Patent Document 1 discloses a resin composition containing: an aromatic polycarbonate resin using as a chain-end terminator a product of a reaction between a hydroxyaralkyl alcohol and a lactone; and a glass-based filler whose refractive index differs from that of the aromatic polycarbonate resin by 0.01 or less.
Patent Document 2 discloses a resin composition containing: an aromatic polycarbonate resin; glass fibers whose refractive indices each differ from that of the aromatic polycarbonate resin by 0.015 or less; and polycaprolactone.
Patent Document 3 discloses a resin composition containing: an aromatic polycarbonate resin; glass fibers whose refractive indices each differ from that of the aromatic polycarbonate resin by 0.015 or less; and a polyester resin.
Patent Document 4 discloses a resin composition containing: an aromatic polycarbonate resin; glass fibers whose refractive indices each differ from that of the aromatic polycarbonate resin by 0.015 or less; and an aliphatic polycarbonate resin.
Patent Document 5 discloses a polycarbonate resin composition characterized in that; a difference in refractive index between a glass filler and an aromatic polycarbonate resin is from 0.004 to 0.015 for light having a wavelength of 486 nm, is 0.002 or less for light having a wavelength of 589 nm, and is 0.002 or less for light having a wavelength of 656 nm; the content of the glass filler is from 2 to 40 mass %; and when the composition is molded into a flat plate shape, the flat plate has a total light transmittance of 75% or more and a haze of 35% or less.